Why does my father believe a miracle will heal my brother when he needs real care?

Salam everyone. My father keeps thinking that one day, by Allah’s will, my nonverbal brother with severe autism and seizures will suddenly become 'normal.' I feel like he’s just using faith to cope, but I don’t get why he won’t focus on getting proper support instead. My brother has finished school and now stays home all day, which leads to destructive habits-screaming, messing, hitting, scratching-that we all have to handle. Even though we can afford a caregiver, my dad is too worried to let a trained professional look after him. He fears my brother might fall or get hurt, but these people know what they’re doing, unlike my dad. It’s exhausting, and my brother is basically stuck at home like a prisoner. My father has also been abusive, verbally and physically, to both of us, though he stopped hurting my brother. But the harm is done. I wonder, why would Allah grant a wish to someone like that? Plus, it’s not scientifically possible for him to suddenly be neurotypical. Any advice?